In the automobile industry, lightweight components, which apart from a low weight must also have high strength and rigidity, are used to a considerable degree. Frequently, corresponding lightweight components, for example in the case of a vehicle body, also serve as outer skin panels so that their surfaces must also meet correspondingly high standards. One approach for achieving this aim is to combine different materials. Thus, for example, German patent application DE 10 2004 022 677 A1 discloses composite components which, as a sandwich structure, consist of two outer sheet metal plates and one inner polymer layer, the polymer layer being designed as foam material. However, in order to bond the metal parts to the polymer layer, an adhesive or adhesion promoter must be carefully applied. In addition, a double conveyer is disclosed, which is intended to limit the thickness of the reactive foam layer and to assist the reactive foaming process by heatable sections.
Furthermore, the published European Patent Application EP 1 504 892 A1 discloses the provision of a polymer layer consisting of a polyamide or a polyamide-polyethylene blend between two sheet metal plates. This composite component is, however, capable of improvement with respect to its weight.